CVE-2021-45575 in RBK752
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects RBK752 before 3.2.16.6, RBR750 before 3.2.16.6, RBS750 before 3.2.16.6, RBK852 before 3.2.16.6, RBR850 before 3.2.16.6, and RBS850 before 3.2.16.6.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/28/2021
The vulnerability identified as CVE-2021-45575 represents a critical command injection flaw affecting multiple NETGEAR router models within the RBK and RBR series. This vulnerability specifically impacts devices running firmware versions prior to 3.2.16.6, creating a significant security risk for network infrastructure deployments. The flaw allows authenticated users to execute arbitrary commands on the affected devices, fundamentally compromising the integrity and security posture of the network equipment. This type of vulnerability falls under CWE-77 which specifically addresses command injection vulnerabilities in software systems where user-supplied data is improperly incorporated into system commands without adequate sanitization or validation.
The technical implementation of this vulnerability stems from insufficient input validation within the web interface of these routers. When authenticated users submit specific inputs through the management interface, the system fails to properly sanitize or escape these inputs before incorporating them into system commands. This creates a direct pathway for attackers to inject malicious commands that execute with the privileges of the web server process. The vulnerability is particularly concerning because it requires only authentication to exploit, meaning that an attacker who has gained access to the router's management interface can leverage this flaw to escalate their privileges and execute arbitrary code on the device. The attack vector typically involves manipulating form fields or API endpoints that handle user input, where the system processes the input without proper validation mechanisms.
The operational impact of this vulnerability extends beyond simple unauthorized command execution, as it fundamentally undermines the security of the entire network infrastructure. Once exploited, attackers can gain full control over the affected router, potentially leading to man-in-the-middle attacks, network traffic interception, or complete network compromise. The affected devices include several popular router models from NETGEAR's business and enterprise product lines, making this vulnerability particularly dangerous for organizations relying on these devices for network security. The vulnerability creates a persistent backdoor that could remain undetected for extended periods, allowing attackers to maintain long-term access to the network. This aligns with ATT&CK technique T1059.001 which covers command and scripting interpreter execution, and T1078 which addresses valid accounts for maintaining access.
Network administrators should immediately implement firmware updates to address this vulnerability, ensuring all affected devices are upgraded to version 3.2.16.6 or later. The recommended mitigation strategy includes implementing network segmentation to limit the potential impact of exploitation, monitoring for suspicious network activity, and conducting thorough security assessments of all router deployments. Additionally, organizations should enforce strict access controls and implement multi-factor authentication for router management interfaces. The vulnerability highlights the importance of proper input validation and output encoding practices in web applications, as specified in OWASP Top 10 A03:2021. Organizations should also consider implementing network intrusion detection systems to monitor for exploitation attempts and establish incident response procedures for handling potential compromises of network infrastructure devices. Regular security audits of network equipment and firmware updates should become standard practice to prevent similar vulnerabilities from being exploited in the future.